The Copernicus Climate Change Service says that previous year was around 1.25C above the long-term average.
A year ago topped the previous temperature record in Europe, registered in 2019, by a whopping 0.4 degrees Celsius (0.72 Fahrenheit), the EU's Copernicus Climate Change Service said. This new, more complete report from Copernicus says that past year is right at the top of the list. The Copernicus data comes from a constellation of Sentinel satellites that monitor the Earth from orbit.
The year 2020 was 0.6°C warmer than the standard 1981-2010 reference period and around 1.25°C above the 1850-1900 pre-industrial period.
While not quite as drastic as in Europe, temperatures across North America were above average as well. This exceptional warming led to a very active wildfire season.
Only 2016 matched the heat seen in 2020, but that year had a natural El Niño climate event that boosts temperatures. More data on 2020's temperature will be released in the next week or so from other agencies, including Nasa and the UK Met Office.
In 2020 the world was also hit by a record number of hurricanes in the Atlantic, to the extent that the World Meteorological Organization (WMO) ran out of letters to name them.
Past year also saw the highest temperature ever reliably recorded, when in August a California heat wave pushed the temperature at Death Valley in the Mojave Desert up to 54.4C (129.92°F).
After an exceptionally warm winter and autumn in Europe, the continent experienced its hottest year on record in 2020, while the Arctic suffered extreme heat and atmospheric concentrations of planet-warming carbon dioxide continued to rise, the European Union's Copernicus Climate Change Service said on Friday.
"The key here is to - for every year and as quickly as possible - reduce the amount we emit, thus reducing the amount we actually add into the atmosphere", said Freja Vamborg, senior scientist at the Copernicus Climate Change Service.
Vamborg said that it is hard to attribute any temperature differences directly to La Nina, but the cooling effect of the phenomenon may be why December 2020, when La Nina was strengthening, was only the sixth warmest December ever, while most of the other months of the year were in the top three. "So while certainly La Nina had some cooling effect in the last few months, it's likely going to have a bigger impact on 2021 temperatures", he said. Researchers predict that annual average Carbon dioxide concentration at the Mauna Loa recording station in Hawaii will be around 2.29 parts per million (ppm) higher in 2021 than in 2020. "This is 50% higher than the level of 278 ppm in the late 18th Century when widespread industrial activity began".
"Weather patterns linked to the current La Niña event are expected to promote a temporary burst of growth in tropical forests that soak up some of humanity's emissions", the Met Office said, but "CO2 will still continue to build up in the atmosphere, and will exceed 417 ppm for several weeks from April to June".
"Since CO2 accumulates in the atmosphere like water in a bathtub, if we turn down the tap by 7%, the CO2 level just rises a bit more slowly", Stefan Rahmstorf, head of Earth system analysis at the Potsdam Institute for Climate Impact Research, said. We must come together as a global community, to ensure a just transition to a net zero future.